The goal of this project is to characterize avian pancreatic polypeptide (APP) a new pancreatic hormone with regard to regulation of secretion, probable function, nature of precursors and biosynthesis. APP release in chickens is triggered by ingestion of food and the effect of neural and humoral factors in this response will be studied with isolated, denervated gut segments and pancreas slices. The effect of APP upon gut muscle contractions and myoelectric activity will be the subject of an in vitro study. Measurements of the effects of APP in vivo upon hepatic lipogenesis, and plasma lipoprotein will be performed in chickens. Prohormones have been identified for APP and these will be isolated and sequenced. Similar studies are planned with canine pancreatic polypeptide (CPP). A comparison of hormone from different species will be performed.